using System;

namespace MyCompiler {
    class Program {
        public static void Main(string[] args) {
            Console.WriteLine("Hello world!");
            int[] arr = {2,1};
            int firstElement = arr[0];
            int i=0;
            for(i=0; i< arr.Length-1 ; i++){
                arr[i] = arr[i+1];
            }
            arr[i] = firstElement;
            
            foreach(var ele in arr){
                Console.WriteLine("{0}",ele);
            }
        }
    }
}